<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style> 
    .ellipse {
      width: 100px;
      height: 300px;
      background-color: khaki;
      clip-path: ellipse(100px 100px at center top);
      transition: clip-path .5s ease-in-out;
    }

    .ellipse:hover {
      clip-path: ellipse(100px 200px at center top);
    }
</style>
<body>
    <div class="ellipse"></div>
</body>
</html>